<?php
/**
 * Class for working with PO files
 *
 * @version $Id: po.php 718 2012-10-31 00:32:02Z nbachiyski $
 * @package pomo
 * @subpackage po
 */

require_once dirname(__FILE__) . '/translations.php';

define('PO_MAX_LINE_LEN', 79);

ini_set('auto_detect_line_endings', 1);

/**
 * Routines for working with PO files
 */
if (!class_exists('PO')):
    class PO extends Gettext_Translations
    {

        var $comments_before_headers = '';

        /**
         * Exports headers to a PO entry
         *
         * @return string msgid/msgstr PO entry for this PO file headers, doesn't contain newline at the end
         */
        function export_headers()
        {
            $header_string = '';
            foreach ($this->headers as $header => $value) {
                $header_string .= "$header: $value\n";
            }
            $poified = PO::poify($header_string);
            if ($this->comments_before_headers)
                $before_headers = $this->prepend_each_line(rtrim($this->comments_before_headers) . "\n", '# ');
            else
                $before_headers = '';
            return rtrim("{$before_headers}msgid \"\"\nmsgstr $poified");
        }

        /**
         * Exports all entries to PO format
         *
         * @return string sequence of mgsgid/msgstr PO strings, doesn't containt newline at the end
         */
        function export_entries()
        {
            //TODO sorting
            return implode("\n\n", array_map(array('PO', 'export_entry'), $this->entries));
        }

        /**
         * Exports the whole PO file as a string
         *
         * @param bool $include_headers whether to include the headers in the export
         * @return string ready for inclusion in PO file string for headers and all the enrtries
         */
        function export($include_headers = true)
        {
            $res = '';
            if ($include_headers) {
                $res .= $this->export_headers();
                $res .= "\n\n";
            }
            $res .= $this->export_entries();
            return $res;
        }

        /**
         * Same as {@link export}, but writes the result to a file
         *
         * @param string $filename where to write the PO string
         * @param bool $include_headers whether to include tje headers in the export
         * @return bool true on success, false on error
         */
        function export_to_file($filename, $include_headers = true)
        {
            $fh = fopen($filename, 'w');
            if (false === $fh) return false;
            $export = $this->export($include_headers);
            $res = fwrite($fh, $export);
            if (false === $res) return false;
            return fclose($fh);
        }

        /**
         * Text to include as a comment before the start of the PO contents
         *
         * Doesn't need to include # in the beginning of lines, these are added automatically
         */
        function set_comment_before_headers($text)
        {
            $this->comments_before_headers = $text;
        }

        /**
         * Formats a string in PO-style
         *
         * @static
         * @param string $string the string to format
         * @return string the poified string
         */
        function poify($string)
        {
            $quote = '"';
            $slash = '\\';
            $newline = "\n";

            $replaces = array(
                "$slash" => "$slash$slash",
                "$quote" => "$slash$quote",
                "\t" => '\t',
            );

            $string = str_replace(array_keys($replaces), array_values($replaces), $string);

            $po = $quote . implode("${slash}n$quote$newline$quote", explode($newline, $string)) . $quote;
            // add empty string on first line for readbility
            if (false !== strpos($string, $newline) &&
                (substr_count($string, $newline) > 1 || !($newline === substr($string, -strlen($newline))))
            ) {
                $po = "$quote$quote$newline$po";
            }
            // remove empty strings
            $po = str_replace("$newline$quote$quote", '', $po);
            return $po;
        }

        /**
         * Gives back the original string from a PO-formatted string
         *
         * @static
         * @param string $string PO-formatted string
         * @return string enascaped string
         */
        function unpoify($string)
        {
            $escapes = array('t' => "\t", 'n' => "\n", '\\' => '\\');
            $lines = array_map('trim', explode("\n", $string));
            $lines = array_map(array('PO', 'trim_quotes'), $lines);
            $unpoified = '';
            $previous_is_backslash = false;
            foreach ($lines as $line) {
                preg_match_all('/./u', $line, $chars);
                $chars = $chars[0];
                foreach ($chars as $char) {
                    if (!$previous_is_backslash) {
                        if ('\\' == $char)
                            $previous_is_backslash = true;
                        else
                            $unpoified .= $char;
                    } else {
                        $previous_is_backslash = false;
                        $unpoified .= isset($escapes[$char]) ? $escapes[$char] : $char;
                    }
                }
            }
            return $unpoified;
        }

        /**
         * Inserts $with in the beginning of every new line of $string and
         * returns the modified string
         *
         * @static
         * @param string $string prepend lines in this string
         * @param string $with prepend lines with this string
         */
        function prepend_each_line($string, $with)
        {
            $php_with = var_export($with, true);
            $lines = explode("\n", $string);
            // do not prepend the string on the last empty line, artefact by explode
            if ("\n" == substr($string, -1)) unset($lines[count($lines) - 1]);
            $res = implode("\n", array_map(create_function('$x', "return $php_with.\$x;"), $lines));
            // give back the empty line, we ignored above
            if ("\n" == substr($string, -1)) $res .= "\n";
            return $res;
        }

        /**
         * Prepare a text as a comment -- wraps the lines and prepends #
         * and a special character to each line
         *
         * @access private
         * @param string $text the comment text
         * @param string $char character to denote a special PO comment,
         *    like :, default is a space
         */
        function comment_block($text, $char = ' ')
        {
            $text = wordwrap($text, PO_MAX_LINE_LEN - 3);
            return PO::prepend_each_line($text, "#$char ");
        }

        /**
         * Builds a string from the entry for inclusion in PO file
         *
         * @static
         * @param object &$entry the entry to convert to po string
         * @return string|bool PO-style formatted string for the entry or
         *    false if the entry is empty
         */
        function export_entry(&$entry)
        {
            if (is_null($entry->singular)) return false;
            $po = array();
            if (!empty($entry->translator_comments)) $po[] = PO::comment_block($entry->translator_comments);
            if (!empty($entry->extracted_comments)) $po[] = PO::comment_block($entry->extracted_comments, '.');
            if (!empty($entry->references)) $po[] = PO::comment_block(implode(' ', $entry->references), ':');
            if (!empty($entry->flags)) $po[] = PO::comment_block(implode(", ", $entry->flags), ',');
            if (!is_null($entry->context)) $po[] = 'msgctxt ' . PO::poify($entry->context);
            $po[] = 'msgid ' . PO::poify($entry->singular);
            if (!$entry->is_plural) {
                $translation = empty($entry->translations) ? '' : $entry->translations[0];
                $po[] = 'msgstr ' . PO::poify($translation);
            } else {
                $po[] = 'msgid_plural ' . PO::poify($entry->plural);
                $translations = empty($entry->translations) ? array('', '') : $entry->translations;
                foreach ($translations as $i => $translation) {
                    $po[] = "msgstr[$i] " . PO::poify($translation);
                }
            }
            return implode("\n", $po);
        }

        function import_from_file($filename)
        {
            $f = fopen($filename, 'r');
            if (!$f) return false;
            $lineno = 0;
            while (true) {
                $res = $this->read_entry($f, $lineno);
                if (!$res) break;
                if ($res['entry']->singular == '') {
                    $this->set_headers($this->make_headers($res['entry']->translations[0]));
                } else {
                    $this->add_entry($res['entry']);
                }
            }
            PO::read_line($f, 'clear');
            if (false === $res) {
                return false;
            }
            if (!$this->headers && !$this->entries) {
                return false;
            }
            return true;
        }

        function read_entry($f, $lineno = 0)
        {
            $entry = new Translation_Entry();
            // where were we in the last step
            // can be: comment, msgctxt, msgid, msgid_plural, msgstr, msgstr_plural
            $context = '';
            $msgstr_index = 0;
            $is_final = create_function('$context', 'return $context == "msgstr" || $context == "msgstr_plural";');
            while (true) {
                $lineno++;
                $line = PO::read_line($f);
                if (!$line) {
                    if (feof($f)) {
                        if ($is_final($context))
                            break;
                        elseif (!$context) // we haven't read a line and eof came
                            return null;
                        else
                            return false;
                    } else {
                        return false;
                    }
                }
                if ($line == "\n") continue;
                $line = trim($line);
                if (preg_match('/^#/', $line, $m)) {
                    // the comment is the start of a new entry
                    if ($is_final($context)) {
                        PO::read_line($f, 'put-back');
                        $lineno--;
                        break;
                    }
                    // comments have to be at the beginning
                    if ($context && $context != 'comment') {
                        return false;
                    }
                    // add comment
                    $this->add_comment_to_entry($entry, $line);
                } elseif (preg_match('/^msgctxt\s+(".*")/', $line, $m)) {
                    if ($is_final($context)) {
                        PO::read_line($f, 'put-back');
                        $lineno--;
                        break;
                    }
                    if ($context && $context != 'comment') {
                        return false;
                    }
                    $context = 'msgctxt';
                    $entry->context .= PO::unpoify($m[1]);
                } elseif (preg_match('/^msgid\s+(".*")/', $line, $m)) {
                    if ($is_final($context)) {
                        PO::read_line($f, 'put-back');
                        $lineno--;
                        break;
                    }
                    if ($context && $context != 'msgctxt' && $context != 'comment') {
                        return false;
                    }
                    $context = 'msgid';
                    $entry->singular .= PO::unpoify($m[1]);
                } elseif (preg_match('/^msgid_plural\s+(".*")/', $line, $m)) {
                    if ($context != 'msgid') {
                        return false;
                    }
                    $context = 'msgid_plural';
                    $entry->is_plural = true;
                    $entry->plural .= PO::unpoify($m[1]);
                } elseif (preg_match('/^msgstr\s+(".*")/', $line, $m)) {
                    if ($context != 'msgid') {
                        return false;
                    }
                    $context = 'msgstr';
                    $entry->translations = array(PO::unpoify($m[1]));
                } elseif (preg_match('/^msgstr\[(\d+)\]\s+(".*")/', $line, $m)) {
                    if ($context != 'msgid_plural' && $context != 'msgstr_plural') {
                        return false;
                    }
                    $context = 'msgstr_plural';
                    $msgstr_index = $m[1];
                    $entry->translations[$m[1]] = PO::unpoify($m[2]);
                } elseif (preg_match('/^".*"$/', $line)) {
                    $unpoified = PO::unpoify($line);
                    switch ($context) {
                        case 'msgid':
                            $entry->singular .= $unpoified;
                            break;
                        case 'msgctxt':
                            $entry->context .= $unpoified;
                            break;
                        case 'msgid_plural':
                            $entry->plural .= $unpoified;
                            break;
                        case 'msgstr':
                            $entry->translations[0] .= $unpoified;
                            break;
                        case 'msgstr_plural':
                            $entry->translations[$msgstr_index] .= $unpoified;
                            break;
                        default:
                            return false;
                    }
                } else {
                    return false;
                }
            }
            if (array() == array_filter($entry->translations, create_function('$t', 'return $t || "0" === $t;'))) {
                $entry->translations = array();
            }
            return array('entry' => $entry, 'lineno' => $lineno);
        }

        function read_line($f, $action = 'read')
        {
            static $last_line = '';
            static $use_last_line = false;
            if ('clear' == $action) {
                $last_line = '';
                return true;
            }
            if ('put-back' == $action) {
                $use_last_line = true;
                return true;
            }
            $line = $use_last_line ? $last_line : fgets($f);
            $line = ("\r\n" == substr($line, -2)) ? rtrim($line, "\r\n") . "\n" : $line;
            $last_line = $line;
            $use_last_line = false;
            return $line;
        }

        function add_comment_to_entry(&$entry, $po_comment_line)
        {
            $first_two = substr($po_comment_line, 0, 2);
            $comment = trim(substr($po_comment_line, 2));
            if ('#:' == $first_two) {
                $entry->references = array_merge($entry->references, preg_split('/\s+/', $comment));
            } elseif ('#.' == $first_two) {
                $entry->extracted_comments = trim($entry->extracted_comments . "\n" . $comment);
            } elseif ('#,' == $first_two) {
                $entry->flags = array_merge($entry->flags, preg_split('/,\s*/', $comment));
            } else {
                $entry->translator_comments = trim($entry->translator_comments . "\n" . $comment);
            }
        }

        function trim_quotes($s)
        {
            if (substr($s, 0, 1) == '"') $s = substr($s, 1);
            if (substr($s, -1, 1) == '"') $s = substr($s, 0, -1);
            return $s;
        }
    }
endif;
